1N5237B-TP Zener Diode Equivalent & Substitute Parts

Part Overview

The 1N5237B-TP is an 8.2 V, 500 mW Zener diode manufactured by Micro Commercial Co in a DO-35 axial through-hole package. This component is classified as obsolete, necessitating identification of equivalent substitute parts for ongoing design requirements and production continuity. Substitute parts must maintain electrical performance within the specified tolerance and mechanical compatibility with the original package designation.

Substiute Parts

1N5237B-TP

Micro Commercial CoIn Stock: 7911N5237B-TP Datasheet

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1N5237B

Microchip TechnologyIn Stock: 364551N5237B Datasheet

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1N5237BTR

Fairchild SemiconductorIn Stock: 599881N5237BTR Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 1N5237B-TP are identified based on strict electrical and mechanical parameter matching. The following criteria determine substitution eligibility:

Primary Matching Criteria:

• Zener voltage: 8.2 V nominal
• Tolerance: ±5%
• Power rating: 500 mW minimum
• Impedance (maximum): 8 Ohms
• Reverse leakage current: 3 µA @ 6.5 V
• Package type: DO-35 (DO-204AH) axial through-hole

Acceptable Parameter Variations:

• Forward voltage (Vf) @ 200 mA: Substitute parts may exceed the original 1.1 V specification up to 1.5 V without affecting circuit functionality in standard Zener regulation applications
• Operating temperature range: Substitute parts with extended temperature ranges (-65°C to 200°C) provide enhanced performance margins and are acceptable for applications within the original operating window

All substitute parts listed maintain identical electrical performance for the core Zener regulation function while offering improved availability and active product status.

Parameter Comparison

Engineering Selection Recommendations

1N5237B (Microchip Technology)

This substitute part maintains full electrical equivalence to the original 1N5237B-TP across all critical Zener regulation parameters. The extended operating temperature range (-65°C to 175°C) provides additional thermal margin. However, this part is classified as RoHS non-compliant, which may impact suitability for applications subject to RoHS3 compliance requirements. The forward voltage specification of 1.5 V @ 200 mA is within acceptable limits for standard Zener diode applications.

1N5237BTR (Fairchild Semiconductor)

This substitute part provides complete electrical compatibility with the original 1N5237B-TP, with forward voltage performance (1.2 V @ 200 mA) positioned between the original and the Microchip alternative. The extended operating temperature range (-65°C to 200°C) offers superior thermal performance. This part maintains active product status and is suitable for applications requiring long-term component availability. Compliance documentation for RoHS and REACH status is not provided in the available data.

Selection Basis:

Both substitute parts are electrically equivalent for Zener regulation function. Selection between them should be based on compliance requirements (RoHS status), temperature operating margin requirements, and supplier availability. The 1N5237BTR offers the widest operating temperature range and represents the most conservative engineering choice for applications requiring extended thermal performance.

Frequently Asked Questions (FAQ)

Q: Can the 1N5237B (Microchip) be used as a direct replacement for the 1N5237B-TP?

A: Yes. Both parts share identical Zener voltage (8.2 V), tolerance (±5%), power rating (500 mW), impedance (8 Ohms), and reverse leakage specifications (3 µA @ 6.5 V). The DO-35 package is mechanically identical. The forward voltage difference (1.5 V vs. 1.1 V @ 200 mA) does not affect Zener regulation performance in standard applications.

Q: What is the significance of the forward voltage difference between substitute parts?

A: Forward voltage (Vf) applies to the diode's forward-biased conduction mode, which is not the primary operating condition for Zener regulation circuits. In reverse-biased Zener operation, forward voltage is not a functional parameter. Differences in Vf between 1.1 V and 1.5 V are acceptable for equivalent substitution.

Q: Are the substitute parts mechanically compatible with the original DO-35 package?

A: Yes. All substitute parts use the DO-35 (DO-204AH) axial through-hole package, which is mechanically and electrically identical to the original. No PCB layout or mechanical assembly modifications are required.

Q: Why does the 1N5237B-TP have a narrower operating temperature range than the substitutes?

A: The original part specifies -55°C to 150°C, while substitutes extend to -65°C to 175°C or -65°C to 200°C. This reflects manufacturing process improvements and thermal design enhancements in newer production. Substitute parts with extended ranges remain fully compatible with applications designed for the original temperature window.

Q: What is the impact of RoHS non-compliance on the Microchip 1N5237B?

A: RoHS non-compliance indicates the part may contain restricted substances (lead, cadmium, mercury, etc.). Selection of this part requires verification that the end application is not subject to RoHS3 regulatory requirements. The original 1N5237B-TP is ROHS3 compliant.

Q: Can both substitute parts be used interchangeably in the same design?

A: Yes. Both the 1N5237B (Microchip) and 1N5237BTR (Fairchild) meet all electrical and mechanical substitution criteria. Selection between them is based on compliance requirements, supplier availability, and thermal margin preferences rather than functional performance differences.